cmd/compile: don't re-typecheck while importing

The imported code is already typechecked. NodAddrAt typechecks its
argument, which is unnecessary here and leads to errors when
typechecking unexported field references in other packages' code.

Mark the node is question as already typechecked, so we don't
retypecheck it.

Fixes #50148

Change-Id: I9789e3e7dd4d58ec095675e27b1c98389f7a0c44
Reviewed-on: https://go-review.googlesource.com/c/go/+/371554
Trust: Keith Randall <khr@golang.org>
Run-TryBot: Keith Randall <khr@golang.org>
Trust: Dan Scales <danscales@google.com>
Reviewed-by: Dan Scales <danscales@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>

3 files changed, 38 insertions, 0 deletions

diff --git a/test/typeparam/structinit.dir/a.go b/test/typeparam/structinit.dir/a.go
new file mode 100644
index 0000000000..c76d1551ad
--- /dev/null
+++ b/test/typeparam/structinit.dir/a.go
@@ -0,0 +1,15 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package a
+
+type S[T any] struct {
+}
+
+func (b *S[T]) build() *X[T] {
+	return &X[T]{f:0}
+}
+type X[T any] struct {
+	f int
+}
diff --git a/test/typeparam/structinit.dir/b.go b/test/typeparam/structinit.dir/b.go
new file mode 100644
index 0000000000..40a929bcae
--- /dev/null
+++ b/test/typeparam/structinit.dir/b.go
@@ -0,0 +1,12 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package b
+
+import "./a"
+
+func B() {
+	var x a.S[int]
+	_ = x
+}
diff --git a/test/typeparam/structinit.dir/main.go b/test/typeparam/structinit.dir/main.go
new file mode 100644
index 0000000000..c564171879
--- /dev/null
+++ b/test/typeparam/structinit.dir/main.go
@@ -0,0 +1,11 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+import "./b"
+
+func main() {
+	b.B()
+}